I have learned about Geometry basic here, then I want to curious how many polygons or shape in the world at all ? only till to 8 (Octagon) or is there more polygons ?

There are many more! 9 sides? Nonagon, 10 sides? Decagon. And so on and so on until there are so many sides you could hardly tell the difference between them and circles.

What is a 24-sided shape called?

A icositetragon An icosogon is 20 sides, and tetra means 4. Put them together and you get 24

1）A polygon is a shape that has STRAIGHT sides. 2）They MUST have sides that are closed. 3）They also NEED to have at least three sides. 4）They have the same number of sides and angles. According to 3 and 4, a circle does not count

What are the names for the polygons above octagon?

9--Nonagon 10--Decagon 11--Hendecagon 12--Dodecagon

What is the difference between a circle, an ellipse, and an oval?

The difference is; with a circle the diameter IS THE SAME all the way around, but with a ellipse the diameter CAN CHANGE as you go around, so a circle is a ellipse but an ellipse is not always a circle. Hope this helps!

why does every shape have gon at the end, like hexagon or a pentagon ect.

-Gon is a suffix for a shape that has a specific number of angles.

Are quadrilaterals always four sided shapes?

Yes they are always four sided.

Who invented the word polygon?

The Greeks invented the word "polygon" probably used by the Greeks well before Euclid wrote one of the primary books on geometry around 300 B.C. "polygon" has been used in English since around 1560 The word comes from two parts: "poly-" = many "-gon" = angle (or knee)

"obtuse" is the name of an angle that has more than 90° degrees and less than 180°.

Why is squares rectangles,but rectangles is not squares?Explain

A rectangle has four sides and four right angles, which can also be said about squares. However, a square has four _equal_ sides, which can not be said about all rectangles.

Main content

5th grade

Course: 5th grade > Unit 16

Lesson 3: Properties of shapes

Polygons review

Google Classroom

Review the term polygon and name polygons with up to 8 sides. Then, try some practice problems.

What is a polygon?

A polygon is a closed figure with at least 3 straight sides.

Practice set 1

Problem 1A

Current

Is the following figure a polygon?

Want to learn more about recognizing shapes? Check out this video.

Identifying polygons

Polygons can be named by their number of sides.

Number of sides	Name
3	Triangle
4	Quadrilateral
5	Pentagon
6	Hexagon
7	Heptagon
8	Octagon

Practice set 2

Problem 2A

Current

Which of these shapes are quadrilaterals?

Want to try more problems like this? Check out this exercise

Want to join the conversation?

Sort by:

abdan syakuran
Posted 6 years ago. Direct link to abdan syakuran's post “I have learned about Geom...”
I have learned about Geometry basic here, then I want to curious how many polygons or shape in the world at all ? only till to 8 (Octagon) or is there more polygons ?
Comment on abdan syakuran's post “I have learned about Geom...”
(55 votes)
- grayson.lee
  Posted 6 years ago. Direct link to grayson.lee's post “There are many more! 9 si...”
  There are many more! 9 sides? Nonagon, 10 sides? Decagon. And so on and so on until there are so many sides you could hardly tell the difference between them and circles.
  Comment on grayson.lee's post “There are many more! 9 si...”
  (60 votes)
ULTIMATEGUYZ
Posted 5 years ago. Direct link to ULTIMATEGUYZ's post “What is a 24-sided shape ...”
What is a 24-sided shape called?
Comment on ULTIMATEGUYZ's post “What is a 24-sided shape ...”
(26 votes)
- Hecretary Bird
  Posted 5 years ago. Direct link to Hecretary Bird's post “A icositetragon An icosog...”
  A icositetragon
  An icosogon is 20 sides, and tetra means 4.
  Put them together and you get 24
  Comment on Hecretary Bird's post “A icositetragon An icosog...”
  (40 votes)
bh4troy
Posted 7 years ago. Direct link to bh4troy's post “What's a polygon”
What's a polygon
Comment on bh4troy's post “What's a polygon”
(18 votes)
- Zelong Huang
  Posted 2 years ago. Direct link to Zelong Huang's post “1）A polygon is a shape th...”
  1）A polygon is a shape that has STRAIGHT sides.
  2）They MUST have sides that are closed.
  3）They also NEED to have at least three sides.
  4）They have the same number of sides and angles.
  
  According to 3 and 4, a circle does not count
  (4 votes)
Faaty
Posted 5 years ago. Direct link to Faaty's post “What is the difference be...”
What is the difference between a circle, an ellipse, and an oval?
Comment on Faaty's post “What is the difference be...”
(13 votes)
- GoPro47😃
  Posted 5 years ago. Direct link to GoPro47😃's post “The difference is; with a...”
  The difference is; with a circle the diameter IS THE SAME all the way around, but with a ellipse the diameter CAN CHANGE as you go around, so a circle is a ellipse but an ellipse is not always a circle. Hope this helps!
  (35 votes)
Khalid
Posted 5 years ago. Direct link to Khalid's post “What are the names for th...”
What are the names for the polygons above octagon?
(15 votes)
- Lewis
  Posted 5 years ago. Direct link to Lewis's post “9--Nonagon 10--Decagon 1...”
  9--Nonagon
  10--Decagon
  11--Hendecagon
  12--Dodecagon
  Comment on Lewis's post “9--Nonagon 10--Decagon 1...”
  (24 votes)
bbiekert
Posted 6 years ago. Direct link to bbiekert's post “why does every shape have...”
why does every shape have gon at the end, like hexagon or a pentagon ect.
Comment on bbiekert's post “why does every shape have...”
(12 votes)
- Veronica Viticella
  Posted 6 years ago. Direct link to Veronica Viticella's post “-Gon is a suffix for a sh...”
  -Gon is a suffix for a shape that has a specific number of angles.
  Comment on Veronica Viticella's post “-Gon is a suffix for a sh...”
  (16 votes)
Lavanya Mohanram
Posted 4 months ago. Direct link to Lavanya Mohanram's post “Are quadrilaterals always...”
Are quadrilaterals always four sided shapes?
Comment on Lavanya Mohanram's post “Are quadrilaterals always...”
(10 votes)
- blanton.eidur
  Posted 4 months ago. Direct link to blanton.eidur's post “Yes they are always four ...”
  Yes they are always four sided.
  (9 votes)
Rosie YANG
Posted 6 years ago. Direct link to Rosie YANG's post “Who invented the word pol...”
Who invented the word polygon?
Comment on Rosie YANG's post “Who invented the word pol...”
(7 votes)
- davebetts
  Posted 6 years ago. Direct link to davebetts's post “The Greeks invented the w...”
  The Greeks invented the word "polygon" probably used by the Greeks well before Euclid wrote one of the primary books on geometry around 300 B.C.
  
  "polygon" has been used in English since around 1560
  
  The word comes from two parts:
  "poly-" = many
  "-gon" = angle (or knee)
  Comment on davebetts's post “The Greeks invented the w...”
  (14 votes)
ejandersen
Posted 2 months ago. Direct link to ejandersen's post “whats a obtuse again”
whats a obtuse again
(4 votes)
- Tomodino (≧▽≦)
  Posted 2 months ago. Direct link to Tomodino (≧▽≦)'s post “"obtuse" is the name of a...”
  "obtuse" is the name of an angle that has more than 90° degrees and less than 180°.
  (15 votes)
Da'Laya
Posted 5 years ago. Direct link to Da'Laya's post “Why is squares rectangles...”
Why is squares rectangles,but rectangles is not squares?Explain
(4 votes)
- Jerry Nilsson
  Posted 5 years ago. Direct link to Jerry Nilsson's post “A rectangle has four side...”
  A rectangle has four sides and four right angles, which can also be said about squares.
  
  However, a square has four equal sides, which can not be said about all rectangles.
  (11 votes)